Writing instrument



FIG. 1 is a front elevational view of a writing instrument showing my new design;

FIG. 2 is a left side elevational view thereof, the right side view being a mirror image of the left side view;

FIG. 3 is a top, left and front perspective view thereof;

FIG. 4 is a left side elevational view of the writing instrument with the cap removed and placed on the bottom, and the writing tip exposed;

FIG. 5 is a rear elevational view of the writing instrument of FIG. 1; and,

FIG. 6 is a bottom perspective view of the writing instrument with the cap removed and not shown for convenience of illustration, and the writing tip exposed. 

The ornamental design for a writing instrument, as shown and described. 